In its first season, the Showtime series "Homeland" became an unexpected sensation, grabbing viewers' attention with a storyline steeped in suspense. The premise was as timely as the headlines, touching on terrorism fears, patriotism, and how much we could trust the CIA.

We watched as Marine Sergeant Nicholas Brody (Damian Lewis), a prisoner of war who escaped his Middle Eastern captors and was welcomed back to the United States as a hero, was suspected of having been "turned" into an anti-U.S. sleeper agent. Hot on his trail was CIA operative Carrie Mathison (Claire Danes), who didn't buy Brody's story, and was convinced he was lying low, waiting to attack.

Viewers were torn between sympathizing with Carrie, and questioning her instincts, because of the bipolar condition she was hiding from her CIA superiors. We also found out that Brody's loyalties were tangled. When Brody and Carrie began an affair, their personal and political agendas got even more twisted.

All that Emmy-winning, delicious uncertainty went down the drain, however, in Season 2, when Brody began working with an off-the-books group of CIA insiders. Oh, and he and Carrie discovered they were really in love. Which wasn't great news for Brody's wife (Morena Baccarin) and two kids.

Though there were a few high points in Season 2, overall, it strained credibility, and the emphasis on the Carrie/Brody love story was so misguided and awkwardly handled not even the capable Danes and Lewis could make us buy these two as a lovey-dovey twosome.

The good news is that Season 3 begins with a refreshing jolt of reality. After the climax of Season 2 -- in which hundreds of people die in a terrorist explosion at CIA headquarters -- there are, as you'd expect, major consequences for all involved.

Carrie's CIA mentor, Saul Berenson (Mandy Patinkin), is acting director of the CIA, and dealing with political pressure, and questioning whether the CIA can be trusted to protect the homeland if it can't protect itself.

A grandstanding Senator (writer Tracy Letts, the author of "August: Osage County," in a fine, focused performance) is heading up a Senate Select Committee looking into the explosion, which is being compared to the 9/11 attacks.

He wants a scapegoat, and his attention lands on Carrie. Since she helped Brody, who is Suspect No. 1 in the attacks, escape to the border, Carrie's in a tough position. How much can she cover up about what happened prior to the explosion? How much truth will she be compelled to tell? And can she separate her own feelings for Brody, and her conviction that he was innocent of the attack, from what her job requires her to do?

"Homeland" Season 3 premiere

When: 9 p.m. Sunday

Channel: Showtime

Complicating matters further are Carrie's fragile emotional state and her tendency to go off her meds.

The best moments in the Season 3 premiere have to do with Carrie trying to navigate her way through these turbulent waters, and maintain her equilibrium. By this point, Danes is totally assured at showing us just how out of control Carrie is, even as she insists she's got everything together. Whether she should remain in the CIA is definitely a matter open to discussion, but Danes makes us care about what happens to Carrie as she does her best to cope.

The premiere episode doesn't give us any hint of where Brody may be -- and Lewis doesn't appear -- which seems only logical, considering he's on the run. But we feel the impact of his actions by seeing the fractured state of his family. His wife, Jessica, is trying to survive media scrutiny on the family of the "traitor," there's little money coming in, and daughter Dana (Morgan Saylor) is still trying to recover from everything that's happened.

It doesn't seem necessary to spend so much time on perpetually sulky teen Dana, but her situation definitely speaks to the pain that has rained down on the family because of what Brody has done, and the secrets he kept.

By the time the first episode of the season is over -- when Carrie suffers a surprise betrayal -- its heroine may be on shaky ground. But it feels like "Homeland" has again found its focus.